Field
The disclosed concept pertains generally to electrical switching apparatus, such as for example, circuit breakers. The disclosed concept also pertains to retention systems for electrical switching apparatus.
Background Information
Electrical switching apparatus are used to protect electrical circuitry from damage due to a trip condition, such as, for example, an overcurrent condition, an overload condition, an undervoltage condition, a relatively high level short circuit or fault condition, a ground fault or arc fault condition. Molded case circuit breakers, for example, include at least one pair of separable contacts which are operated either manually by way of a handle located on the outside of the case, or automatically by way of a trip unit in response to the trip condition.
Some molded case circuit breakers have wires that attach to internal components and exit the circuit breaker for use with external systems. In order for the circuit breaker to be properly certified, such as, for example and without limitation, to be properly certified by Underwriters Laboratories Inc., headquartered in Northbrook, Ill., the wiring configuration must pass a pull test. The pull test generally involves disconnecting the wires from the internal components and applying a pull force to the wires external the circuit breaker for one minute. During the test, there can be no displacement within the wire routing.
Due to advancements in technology, more features have been added internally to circuit breakers. As a result, wires having different diameters (i.e., gauges) have been employed to accommodate the internal changes. A significant drawback caused by employing the different wires is that the pull test is not always satisfied. More specifically, pull testing the different wires results in undesirable displacement of the individual wires, thereby failing the test and the ability to get the appropriate certification.
There is, therefore, room for improvement in electrical switching apparatus and in retention systems therefor.